1. Field of the Invention
The present invention relates to an air bag system for an automobile, and more specifically, to a control for the air bag system.
2. Description of the Prior Art
Conventionally, there has been known an automobile equipped with an air bag system for preventing a passenger from being injured in case of a collision. Japanese Patent Publication No. 52-5128 discloses an air bag system in which an air bag for absorbing a collision shock is inflated by means of an inflator actuated electrically in the case of a collision so as to contact with a passenger's breast. As a result, a crash energy caused by the collision is absorbed by the inflated air bag so that the passenger is prevented from a shock of the collision and therefore kept safe.
U.S. Pat. No. 3,911,391 discloses an air bag system in which a vehicle speed is sensed by a sensor and an operation of the air bag system is controlled in accordance with the vehicle speed sensed.
U.S. Pat. No. 3,851,305 discloses an air bag system which is controlled in accordance with signals from a deceleration sensor and a collision sensor.
U.S. Pat. No. 4,359,715 discloses a diagnostic system for an air bag system.
U.S. Pat. No. 3,687,213 discloses a control system for controlling an air bag system based on radio signals.
U.S. Pat. No. 3,741,584 discloses an air bag system provided with separate inflation passages actuated independently.
U.S. Pat. No. 3,966,224 discloses an air bag system provided with a plurality of inflation volumes actuated by respective impacts.
U.S. Pat. No. 3,874,695 discloses an air bag system in which a gas generator is stepwise actuated in accordance with impact levels.
It should, however, be noted that these conventional air bag systems are disadvantageous in adaptability. Generally, an air bag in such systems is mounted so as to be stationary on a car. An inflating time period is basically constant. In addition, a timing of initiation of inflation is not controllable. On the other hand, a seating condition of a passenger on a seat in the car usually varies, person, to person changing a distance between the passenger and the air bag. It follows that a timing when the air bag contacts with the passenger's breast varies depending on a seating condition of the passenger in case of collision and that the air bag may not contact with the passenger's breast in some cases. Thus, the conventional air bag system is not reliable in protecting the passenger.